Task 3.8 - pressurized fluidized-bed combustion
The focus of this work on pressurized fluidized-bed combustion (PFBC) is the development of sorbents for in-bed alkali control. The goal is to generate fundamental process information for development of a second-generation PFBC. Immediate objectives focus on the performance of sulfur sorbents, fate of alkali, and the Resource Conservation and Recovery Act (RCRA) heavy metals. The studies reported here focus on emission control strategies applied in the bed. Data from shakedown testing, alkali sampling, sulfur sorbent performance tests, and refuse-derived fuel (RDF) and lignite combustion tests are presented in detail. Initial results from the characterization of alkali gettering indicate that in-bed getters can remove a significant amount of alkali from the bed. Using kaolin as a sorbent, sodium levels in the flue gas were reduced from 3.6 ppm to less than 0.22 ppm. Sulfur was also reduced by 60% using the kaolin sorbent. Preliminary sulfur sorbent testing, which was designed to develop a reliable technique to predice sorbent performance, indicate that although the total sulfur capture is significantly lower than that observed in a full-scale PFBC, the emission trends are similar. RDF and RDF-lignite fuels had combustion efficiencies exceeding 99.0% in all test cases. Sulfur dioxide emission was significantly lower for the RDF fuels than for lignite fuel alone. Nitrogen oxide emission was also lower for the RDF-based fuels than for the lignite fuel. Both emission gases were well below current regulatory limits. Carbon monoxide and hydrocarbon emissions appeared to be slightly higher for the fuels containing RDF, but were below 9 ppm for the worst case. Analysis of volatile organic compound emission does not indicate an emission problem for these fuels. Chromium appears to be the only RCRA metal that might present some disposal problem; however, processing of the RDF with the wet resource recovery method should reduce chromium levels. 2 refs., 13 figs., 15 tabs.
- Research Organization:
- Univ. of North Dakota, Grand Forks, ND (United States). Energy and Environmental Research Center
- Sponsoring Organization:
- USDOE Assistant Secretary for Fossil Energy, Washington, DC (United States)
- DOE Contract Number:
- FC21-93MC30097
- OSTI ID:
- 574194
- Report Number(s):
- DOE/MC/30097-5673; ON: DE97005402; TRN: 98:001190
- Resource Relation:
- Other Information: PBD: Mar 1995
- Country of Publication:
- United States
- Language:
- English
Similar Records
Capture of alkali during pressurized fluidized-bed combustion using in-bed sorbents
Construction and utilization of a large-scale coal-fired pressurized fluidized-bed facility